The invention relates to a seeder wherein the functions of the main components are electronically controlled.
More specifically, electronic means are employed for adjusting the speed of the distributors to the machine forward speed, and for acting upon the devices that control the seed fall, with a view to making them evenly spread over the ground, and penetrate same at a constant depth. There are known pneumatic seeders consisting substantially of a container divided in two by a revolving disk, provided with a plurality of holes all over its periphery.
One of the compartments functions as a reservoir for the seeds, while the other is a chamber kept under vacuum by suitable suction means.
By effect of vacuum the seeds adhere to the holes present on the disk, which revolves about a horizontal axis.
During such revolution, the holes pass before an area that is not subjected to vacuum, from where the seeds may fall to the ground. In the known seeders the distributor disks are rotated by the machine wheels, through mechanical transmission gears.
This system, however, is not free of some drawbacks and inconveniences: First of all, the speed of revolution of the distributor is linked to the forward speed of the machine by a limited number of fixed ratios. Secondly, this system entails as a consequence the building of very heavy costly and structurally complicated machines which, in case of wear, require considerable maintenance costs.
Italian patent applcation 20162 A/87 describes a seeder of substantially the above kind, but providing electronic devices that allow to adjust the speed of revolution of the distributors in a continuous way, so as to make it fit moment by moment to the forward speed of the machine.